android學習之--網格視圖(GridView)和圖像切換器(ImageSwitcher)

GridView用於在界面上按行、列分布顯示多個組件。GridView和ListView有共同父類：AbsListView。GridView與ListView的區別在於：ListView只在一個方向上分布，GridView在兩個方向上分布。所以使用GridView時一般都指定numColumns大於1，否則該屬性默認值為1，就意味著改GridView只有一列，那就變成了ListView

GridView的xml屬性

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ImageSwitcher由FrameLayout派生而出，ImageSwitcher組件與ImageView很相似，但是ImageSwitcher多一個功能：它所顯示的圖片切換時可以設置動畫效果。

使用ImageSwitcher時往往需要為它設置一個ImageSwitcher.ViewFactory的makeView()方法來負責顯示ImageView

下面結合GridView和ImageSwitcher來實現一個例子

（1）activity_main.xml 布局GridView和ImageSwitcher

（2）img.xml 布局imageView 用於顯示GridView的圖片

（3）MainActivity.java

package com.example.viewimage;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.GridView;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.SimpleAdapter;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {
	
	//定義組件
	private GridView gredView = null;
	private ImageSwitcher imageSwt =null;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//獲取布局組件
		gredView = (GridView) findViewById(R.id.grid);
		imageSwt = (ImageSwitcher) findViewById(R.id.imageSwitch);
		//圖片
		final int images[] = new int[]{
				R.drawable.name01,R.drawable.name02,R.drawable.name03,R.drawable.name04,
				R.drawable.name05,R.drawable.name06,R.drawable.name07,R.drawable.name08,
				R.drawable.name09,R.drawable.name10,R.drawable.name11,R.drawable.name12,
				R.drawable.name13,R.drawable.name14,R.drawable.name15,R.drawable.name16
		};
		//創建list集合，存儲圖片
		List> list = new ArrayList>();
		for(int i=0;i map = new HashMap();
			map.put("img", images[i]);
			list.add(map);
		}
		//設置圖片更換效果
		//淡入效果
		imageSwt.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
		//淡出效果
		imageSwt.setOutAnimation(AnimationUtils.loadAnimation(this,android.R.anim.fade_out));
		//設置圖片轉換效果
		imageSwt.setFactory(new ViewFactory() {
			
			@Override
			public View makeView() {
				ImageView imageView = new ImageView(MainActivity.this);
				imageView.setLayoutParams(new ImageSwitcher.LayoutParams(300, 300));
				imageView.setScaleType(ScaleType.FIT_CENTER);
				return imageView;
			}
		});
		//設置適配器
		SimpleAdapter simpleAdapter = new SimpleAdapter(this, list, R.layout.img, new String[]{"img"}, new int[]{R.id.img});
		//適配器
		gredView.setAdapter(simpleAdapter);
		//選中事件監聽
		gredView.setOnItemSelectedListener(new OnItemSelectedListener() {

			@Override
			public void onItemSelected(AdapterView parent, View view,
					int position, long id) {
				Log.i("onItemSelected", "onItemSelected");
				imageSwt.setImageResource(images[position]);
			}

			@Override
			public void onNothingSelected(AdapterView parent) {
				// TODO Auto-generated method stub
				
			}
		});
		//點擊事件監聽
		gredView.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView parent, View view,
					int position, long id) {
				Log.i("onItemClick", "onItemClick");
				imageSwt.setImageResource(images[position]);
				
			}
		});
	}


}

運行效果如下：